Trip in Vain, I'm pretty sure, refers to a trip that has already partly begun. Most commonly it's when you are at a connection point on your outbound, and the second segment is so delayed that you'll miss your meeting or whatever at your destination. In that case, you can claim TIV, and the airline should return you to your origin and refund the full value of the ticket.

If you're at your point of origin and the flight is severely delayed (I think it's 2 hours on AA), then you can just ask for a refund.